Underhood Geometry Modification and Transient Coolant Temperature Modelling for Robust Cooling Networks

In this current era, increasing computing power, effort to reduce prototypes’ cost and time, and shorten design-toproduct time urges the need of numerical computation. Higher cooling’s load or requirement is attributed by higher power of engine. Also, higher quantity of heat exchangers and vehicles’ styling resulted limited space at vehicles’ hood. These factors have caused the design job of vehicles’ hood and engine cooling system to be more crucial and challenging. A well designed and robust engine cooling system could sustain in the worst and toughest condition. One of the worst conditions for engine cooling system is sudden keying-off of engine after hill climbing and high speed driving. In this research, three dimensional computational fluids dynamic (CFD) is utilised to model the dynamic air flow at the hood with complicated geometry. On the other hand, one dimensional thermo-fluid model could simulate the system effect after including all the components in engine cooling system. With integration of both models, the transient coolant temperature before and after vehicles’ keying off is simulated and is analysed thoroughly. Front-end hood geometry is morphed to reduce air separation at heat exchangers. Two cone-shaped air directing devices are included to guide higher volume of ram air toward frontal face of heat exchangers. Different heat soak scenarios are simulated and transient temperature trend is observed. The coolant temperature tends to increase tremendously when huge amount of heat soak could not be dissipated away in-time.